Temporal Rate Adaption-Evidence for Supramodal Timing Mechanisms?

描述（由申请人提供）：本研究的长期目标是了解在时间域中管理跨模态交互的原则。本提案的具体目标是确定和表征感知率的超模态定时机制。核心假设是，存在一种活跃的、适应性强的中央计时机制（对秒到分钟的变化做出反应），至少在某种程度上是统一的和非模态的。拟议的研究将依赖于最近发现的跨模态后效，其中重复暴露于脉冲适配器刺激导致后续刺激的脉动速率感知的变化，使得相对较快的适配器导致后来的刺激被感知为较慢，而相对较慢的适配器则相反。即使适配器和测试刺激以不同的方式呈现，并且从未一起呈现，也会发生这种情况。在一系列的心理物理学实验中，这种效应将被测试与不同配置的单峰，双峰，和crossmodal视觉刺激。这些实验将测量后效的强度和方向，因为它随着不同的适配器刺激以及适配器和测试之间的不同空间关系和速率差异而变化。这些实验将提供一个强有力的测试超模态时序假设。另外一组心理物理实验将使用连续的闪光抑制，使参与者在很大程度上不知道视觉刺激，并测试适应是否仍然发生。这将决定效果是否需要有意识的意识（因此可能在很大程度上是认知的）或至少部分是感知的。最后一组实验将通过研究功率谱和稳态频率响应，使用EEG来跟踪时间频率的范围和效果的感知阈值，并将提供听觉和视觉网络之间的因果关系的客观测量，以创建感知效果。这些实验的结果将限制神经元和计算模型的时间处理。时间缺陷与正常衰老以及包括阅读障碍、多动症、帕金森病、抑郁症和精神分裂症在内的疾病有关。一个更好的大脑编码时间的模型有可能提高对这些时间缺陷的理解，并可能对潜在的临床或心理干预产生影响。

DESCRIPTION (provided by applicant): The long-term goal of this research is to understand the principles that govern crossmodal interactions in the temporal domain. The specific objective of this proposal is to identify and to characterize a supramodal timing mechanism for perception of rate. The central hypothesis is that there is a vigorous and adaptive central timing mechanism (responding to changes within the order of seconds to minutes) that is at least to some degree unified and amodal. The proposed studies will rely on a recently discovered crossmodal aftereffect in which repeated exposure to a pulsed adaptor stimulus leads to changes in the perception of the rate of pulsation of subsequent stimuli, such that a relatively fast adaptor lead to later stimuli being perceived as slower, while a relatively slow adaptor does the reverse. This happens even when the adaptor and test stimuli are presented with different modalities and are never presented together. In a series of psychophysical experiments, this effect will be tested with different configurations of unimodal, bimodal, and crossmodal visual stimuli. These experiments will measure the strength and direction of the aftereffect as it varies with different adaptor stimuli and with different spatial relationships and rate differences between adaptor and test. These experiments will provide for a strong test of the supramodal timing hypothesis. An additional set of psychophysical experiments will use continuous flash suppression to render participants are largely unaware of the visual stimuli and test whether adaptation still occurs. This will determine whether the effect requires conscious awareness (and thus may be largely cognitive) or is at least in part perceptual. A final set of experiments will use EEG to track the range of temporal frequencies and the perception threshold of the effect, via the study of the power spectrum and steady state frequency responses, and will provide an objective measure of the causal relationship between auditory and visual networks in creating the perceptual effect. The results of these experiments will place constraints on neuronal and computational models of temporal processing. Timing deficits have been linked to changes due to normal aging as well as to disorders including dyslexia, ADHD, Parkinson's disease, depression, and schizophrenia. A better model of how the brain encodes time has the potential to enhance understanding of these timing deficits and may have implications for potential clinical or psychological interventions.